The risk of Asthma from smoking could cross generations, it seems. New evidence suggests that having a grandmother who smoked during pregnancy may increase the risk of a child developing asthma, Californian researchers report.

“Although our results need to be confirmed, they suggest that smoking during pregnancy has potential transgenerational effects that increase the priority for Smoking prevention among women of childbearing age,” lead author Dr. Frank Gilliland told Reuters Health.

Gilliland and colleagues at the Keck School of Medicine at the University of Southern California, Los Angeles, studied 338 children who had asthma diagnosed by the age of 5 years and compared them with 570 similar but unaffected “control” children.

Having a mother who smoked while pregnant increased the chances that her child would have asthma diagnosed in the first 5 years of life, as well as the risk of persistent Asthma, by 50 percent, the team reports in the medical journal Chest.

Incidentally, children whose mothers stopped smoking before pregnancy were no more likely to develop asthma than children of non-smoking mothers.

On the other hand, having a grandmother who smoked while pregnant (with the mother) doubled the likelihood that her grandchild would become asthmatic.

In a statement, Gilliland said his group speculates that this unexpected result may be the result of DNA damage that “affects the child’s immune system and increases her susceptibility to asthma, which is then passed down to her children.”

SOURCE: Chest, April 2005.